Sway-arrest system improvement

ABSTRACT

A sway arrest system for arresting sway of a suspended load relative to the lifting platform of a crane having a trolley movable along the gantry of the crane and having reeving extending to a load engaging means having at least one pair of opposed sheave nests mounted therein. The load sheaves being arrayed so that the reeving passing over each of the nests of sheaves is acted upon by the spaced sheaves to produce compensating forces to stabilize the load and to arrest sway thereof.

United States Patent [191 Hasegawa et al.

SWAY-ARREST SYSTEM IMPROVEMENT Inventors: Shuji Hasegawa, Tai 6914-2; I-Iideaki Kawata, Tsuchigahara 377, both of Tamano, Japan Filed: Mar. 10, 1972 Appl. No.: 233,586

US. Cl. 212/125, 254/188 Int. Cl. B66c 19/00 Field of Search 212/14, 125, 129;

[56] References Cited UNITED STATES PATENTS 3,308,966 3/1967 Fawell 212/14 FOREIGN PATENTS 0R APPLICATIONS 1,005,348 4/1952 France 254/188 June 19, 1973 T8643 1/1956 Germany 254/188 Primary Examiner-Evon C. Blunk Assistant Examiner-Merle F. Maffei Attorney-Bruce & McCoy [57] ABSTRACT 6 Claims, 4 Drawing Figures SWAY-ARREST SYSTEM IMPROVEMENT CROSS REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates generally to anti-sway devices for inhibiting and arresting sway of a suspended load, and, more particularly, to a sway-arrest load engaging means for large dockside cranes used to load and unload standardized cargo containers.

2. Description of the Prior Art As set forth in application Ser. No. 173,869, many methods and types of devices have been considered for arresting or inhibiting the sway or pendulum motion of a suspended load. In particular, the above-mentioned patent application discloses a load carrying device having fixed sheave nests for use with a pair of moveable trolleys or a single trolley having rolling sheave carriages or mounts adjustably carried therein. In this manner, the reeving supporting the suspended load is angulated, and the fixed sheaves carried within the load supporting spreader produce compensating forces to stabilize the suspended load.

The sway arrest system set forth in application Ser. No. 173,869, however is most effective if the movable head sheaves are used together with the novel headblock sheave design set forth therein. The headblock set forth in application Ser. No. 173,869 when used by itself from a conventional fixed trolley does not generally result in optimum anti-sway performance. In modifying a crane system not originally equipped with a sway-arrest system, the headblock can be modified or replaced with a design as described herein which will provide a substantial measure of sway arresting capability.

The present invention provides a novel headblock configuration which may be used alone to produce desired anti-sway results. This headblock may be used with present trolleys now in wide use in cranes throughout the world, without the need of replacing the trolley system. The headblock system of the present application may also be utilized with other types of trolleys, such as set forth in application Ser. No. 173,869 to further reduce the sway of a suspended load.

SUMMARY OF THE INVENTION The present invention is applicable to an anti-sway suspension system for a crane having a crane structure supporting a gantry with a trolley moveable therealong. The trolley includes a plurality of head sheaves rotatably mounted thereon, with wire rope reeving passed through the head sheaves and connected to a load engaging means suspended therefrom. The load engaging means includes at least one pair of opposed sheave nests mounted therein. Each of the sheave nests lie in parallel planes and have three triangularly spaced, vertically disposed load sheaves rotatably carried therein. Two load sheaves of each sheave nest are generally disposed at the same height, with the third load sheave of each nest being disposed below and between the two upper load sheaves, whereby the reeving depending from the head sheaves mounted on the moveable trolley is reeved through each nest of sheaves with the reeving of the first nest reeved on corresponding sides of the upper load sheaves and around the lower load sheave thereof, while the reeving on the second nest is reeved on opposite corresponding sides of the upper load sheaves and around the lower load sheave thereof.

OBJECTS OF THE INVENTION It is therefore an important object of the present invention to provide a sway-arrest means for inhibiting and arresting sway of an elongated suspended load.

It is a further object of the present invention to provide a sway-arrest system which is adaptable for mounting on existing cranes to replace the load suspension system thereof.

It is another object of the present invention to provide a sway-arrest system for use with the trolleys of existing cranes.

And it is still a further object of the present invention to provide a sway-arrest system having a unique headblock lifting spreader design for stabilizing a container supported thereby.

DESCRIPTION OF THE DRAWINGS Other objects and advantages of the present invention will become apparent when the sway-arrest system is considered in conjunction with the accompanying drawings, wherein:

FIG. 1 is a partial side elevational view of a typical container gantry crane utilizing the present invention while lowering a load into a ships cell;

FIG. 2 is a front elevational view of one side of the novel quick change headblock showing a pair of the nests of three sheaves in tandem;

FIG. 3 is an end elevation of one embodiment of a pair of opposed sheave nests of the present invention; and

FIG. 4 is a schematic of the reeving extending from the trolley around the sheaves in the nests of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention relates to a rope suspension system for a crane in which the narrowest possible sheave arrangement or position is obtained. This positioning of the sheaves provide for least restricted ship cell entry, but still provides a system with good sway dampening characteristics.

FIG. 1 shows the boom portion 11 of a gantry type crane supported upon and movable along a dock portion (not shown). The boom has a trolley 13 movably mounted thereon. The trolley may take any of a norm ber of well known forms, or may contain a pair of movable sheave heads mounted thereon, as set forth in application Ser. No. 173,869.

The trolley 13 is reeved with a plurality of ropes 15, 17 which support a lifting spreader or quick change headblock 19. The quick change headblock is removably attached to a lifting spreader 21, or the like, for supporting an elongated suspended load 23, such as a standardized cargo container. Trolley 13 preferably includes two pair of axially aligned head sheaves 27, 47 mounted on both sides thereof. In this manner, the lifting spreader quick change headblock 19 is suspended from the trolley by the reeving 15, 17 depending from the pairs of head sheaves at each side of the trolley.

The quick change headblock may be attached to different length lifting spreaders, or to a cargo lifting beam, to thereby allow different size containers or cargo to be handled thereby. If desirable, the quick change headblock may be incorporated in or mounted directly on the lifting spreader.

In the preferred embodiment of the present invention, shown more clearly in FIGS. 2 and 3, and schematically in FIG. 4, the quick change headblock is provided with at least one pair of opposed load sheave nests 29. If considered desirable, one o more pairs of sheave nests may be mounted on each side of the lifting spreader. If a pair of sheave nests is mounted at each end of the lifting spreader, only equalized arresting forces will act upon the suspended load, thus eliminating any tendency for the load to rotate about its vertical axis. Each nest of load sheaves is in tandem and includes three triangularly spaced, vertically disposed load sheaves which are axially aligned with and lie in a plane parallel to the adjacent or opposed three sheaves. The upper two load sheaves 31, 39 and 49, 53 in each nest are disposed at generally the same height with the third load sheave 35, 51 of each nest being disposed below and generally midway between the upper two load sheaves.

As shown in FIG. 4, the first wire rope is normally reeved from a wire rope drum (not shown) over a first head sheave 25 of the first pair of axially aligned head sheaves 27 rotatably mounted at one end of the trolley. The wire rope 15 is then reeved downwardly to one of the nests of sheaves mounted in the quick change headblock 19, and around one side of the first load sheave 31 which is rotatably held in position by means of a shaft 33 journaled therein. The wire rope is then reeved downwardly around the outer periphery of the second lower load sheave 35 rotatably held in the sheave nest by means of a shaft 37. The wire rope then turns upwardly and contacts the inside portion of the third load sheave 39 on the side corresponding to the side that the rope contacts the first load sheave. The third load sheave is rotatably held in the nest by means of a shaft, represented by centerline 41. The reeving continues upwardly from the third load sheave over the other or second head sheave 43 of the first pair of head sheaves 27. After passing over head sheave 43 the rope is directed outwardly until it is deadened or attached to an adjustable means (not shown) at the end of the gantry.

The second wire rope 17 is preferably reeved from the same wire rope drum to which the first wire rope 15 is attached. The rope passes over a third head sheave 45 of the second pair of axially aligned head sheaves 47 mounted on the other end of the trolley, and is reeved downwardly to the other sheave nest, where it contacts the inside surface of the fourth load sheave 49 on the side opposite that which the rope 15 contacts the load sheave 31. Load sheave 49 is also rotatably mounted on shaft 33. The wire rope continues downwardly and around the outer periphery of the fifth load sheave 51, mounted on shaft 37, and back up and in contact with the side of the sixth load sheave 53 corresponding to the same side that the rope contacts the fourth load sheave. The wire rope continues upwardly over a fourth head sheave 55 of the pair of sheaves 47, and outwardly to the end of the gantry where it is adjustably deadened.

Each of the pair of sheave nests 29 comprises a separate three-sheave set 31, 35, 39 and 49, 51, 53 through which only one of the wire ropes 15, 17 is reeved. Each of the three-sheave sets lies in the same vertical plane which is parallel to the plane of the other three-sheave set and the axis of each load sheave in a set is disposed at the apex of an isosceles triangle.

In operation, the load is picked up under the overhead crane by the spreader 21 connected to the quick change headblock 19 from a stack of containers or any other suitable pickup point and moved to its deposition area. After the container is horizontally moved from its pickup point to its deposition area, whether this be a shoreside location, on board a ship, or directly into a ship s cell, the container is normally rested over the deposition point, until it stops swaying, and the load load is then deposited in the desired position.

After the container or load had been released, the reeving is retrieved and hoisted to a position where it may be horizontally moved to enable the cycle to be begun again when the trolley reaches the position over the pickup point.

It is therefore an important feature of the present invention that a new and novel apparatus for arresting sway of a load suspended from a gantry crane is provided. It includes the suspension of a lifting spreader by wire ropes reeved from any type trolley through a unique arrangement of sheaves held within nests in the headblock or lifting spreader supporting the load. The nests of sheaves through which the rope is reeved, act upon the reeving to arrest sway of the load.

In tests conducted by applicant, the arrangement of the present invention has markedly reduced the amount of time it takes a swaying spreader supporting a load to come to rest after the load has been transfered from the pick-up point to a position over its deposition point. The arrangement of the present invention has significantly reduced the time it takes a swinging load to come to rest, thereby enabling a crane to be more economically used.

While the invention had been described in considerable detail, it is not limited to such details as have been set forth except as may be necessitated by the appended claims.

We claim:

1. In a Sway-Arrest system for arresting sway of a suspended load relative to the lifting platform of a crane having a trolley movable on the gantry of the crane with a plurality of head sheaves mounted on said trolley, a load engaging means suspended from said head sheaves by reeving passing over said head sheaves, said load engaging means including at least one pair of opposed sheave nests mounted in said load engaging means, each of said sheave nests lying in parallel planes and having three triangularly spaced vertically disposed load sheaves, two of said load sheaves of each nest being disposed at generally the same height with the third load sheave of each nest being disposed below and between the upper two load sheaves whereby the reeving depending from the head sheaves mounted on the moveable trolley is reeved through each nest of sheaves with the reeving of the first nest reeved on corresponding sides of the upper load sheaves and around the lower load sheave thereof while the reeving on the second nest is reeved on opposite corresponding sides of the upper load sheaves and around the lower load sheave thereof.

2. The Sway-Arrest system of claim 1 wherein the bottom load sheave of each sheave nest is generally midway between the upper two load sheaves.

3. The Sway-Arrest system of claim 1 wherein each load sheave in each nest of sheaves is axially aligned with a corresponding load sheave in the opposed nest.

4. The Sway-Arrest system of claim 1 wherein the load engaging means includes at least one pair of sheave nests disposed at each end of the load whereby only equalized arresting forces act upon the suspended load thus eliminating any tendency for load rotation about a vertical axis.

5. In a Sway-Arrest system for arresting sway of an elongated suspended load relative to the lifting platform of a crane having a trolley moveable on the gantry of the crane with a plurality of head sheaves mounted within said trolley, a load engaging means suspended from said head sheaves by reeving passing over said head sheaves, said load engaging means including at least one pair of opposed sheave nests, each of said sheave nests lying in parallel planes and having three triangularly spaced vertically disposed load sheaves,

two of said load sheaves of each nest being disposed at the same height in said nest with the third load sheave disposed below and midway between the upper two load sheaves, each load sheave in each nest being axially aligned with a corresponding load sheave in the opposed nest, and the axis of each load sheave in a nest of sheaves being disposed at the apex of an isosceles triangle whereby the reeving depending from the head sheaves mounted on the movable trolley is reeved about a vertical axis. 

1. In a Sway-Arrest system for arresting sway of a suspended load relative to the lifting platform of a crane having a trolley movable on the gantry of the crane with a plurality of head sheaves mounted on said trolley, a load engaging means suspended from said head sheaves by reeving passing over said head sheaves, said load engaging means including at least one pair of opposed sheave nests mounted in said load engaging means, each of said sheave nests lying in parallel planes and having three triangularly spaced vertically disposed load sheaves, two of said load sheaves of each nest being disposed at generally the same height with the third load sheave of each nest being disposed below and between the upper two load sheaves whereby the reeving depending from the head sheaves mounted on the moveable trolley is reeved through each nest of sheaves with the reeving of the first nest reeved on corresponding sides of the upper load sheaves and around the lower load sheave thereof while the reeving on the second nest is reeved on opposite corresponding sides of the upper load sheaves and around the lower load sheave thereof.
 2. The Sway-Arrest system of claim 1 wherein the bottom load sheave of each sheave nest is generally midway between the upper two load sheaves.
 3. The Sway-Arrest system of claim 1 wherein each load sheave in each nest of sheaves is axially aligned with a corresponding load sheave in the opposed nest.
 4. The Sway-Arrest system of claim 1 wherein the load engaging means includes at least one pair of sheave nests disposed at each end of the load whereby only equalized arresting forces act upon the suspended load thus eliminating any tendency for load rotation about a vertical axis.
 5. In a Sway-Arrest system for arresting sway of an elongated suspended load relative to the lifting platform of a crane having a trolley moveable on the gantry of the crane with a plurality of head sheaves mounted within said trolley, a load engaging means suspended from said head sheaves by reeving passing over said head sheaves, said load engaging means including at least one pair of opposed sheave nests, each of said sheave nests lying in parallel planes and having three triangularly spaced vertically disposed load sheaves, two of said load sheaves of each nest being disposed at the same height in said nest with the third load sheave disposed below and midway between the upper two load sheaves, each load sheave in each nest being axially aligned with a corresponding load sheave in the opposed nest, and the axis of each load sheave in a nest of sheaves being disposed at the apex of an isosceles triangle whereby the reeving depending from the head sheaves mounted on the movable trolley is reeved through each nest of sheaves with the reeving of the first nest reeved on corresponding sides of the upper load sheaves and around the lower load sheave thereof while the reeving on the second nest is reeved on opposite corresponding sides of the upper load sheaves and around the lower load sheavE thereof.
 6. The Sway-Arrest system of claim 5 wherein the load engaging means includes at least one pair of sheave nests disposed at each end of the load whereby only equalized arresting forces act upon the suspended load thus eliminating any tendency for load rotation about a vertical axis. 